linux-mips
[Top] [All Lists]

Re: floating point on Nevada cpu

To: Steve Johnson <stevej@ridgerun.com>
Subject: Re: floating point on Nevada cpu
From: Pete Popov <ppopov@mvista.com>
Date: Thu, 25 Jan 2001 10:02:10 -0800
Cc: "linux-mips@oss.sgi.com" <linux-mips@oss.sgi.com>
Organization: Monta Vista Software
References: <3A6F8F66.6258801@mvista.com> <0101241833281Q.00834@plugh.sibyte.com> <3A6F9814.3E39027@mvista.com> <0101241917341S.00834@plugh.sibyte.com> <3A703E3C.360FB4FF@ridgerun.com>
Sender: owner-linux-mips@oss.sgi.com
Steve,

Steve Johnson wrote:
> 
> Pete,
> 
>     We had a problem in user-space apps all showing 0 for floating-point
> results because we hadn't set the ST0_FR bit to 0, and we had a mis-match
> between user libraries (MIPS3k-compatible) and the floating point registers.
> We noticed the problem when we couldn't run "ps" or "rm" correctly and tracked
> it down from some old postings by Ralf and friends.  Maybe this is your
> problem, too?
> 
>     I added this to our setup call:
> 
>     set_cp0_status(ST0_FR, 0);

Problem solved before I finished my first cup of coffee. Thanks!

I bet this problem will show up here and there depending on how the boot
code sets cp0.  Seems like adding the above line in a mips generic init
routine would be a good thing.

Pete

<Prev in Thread] Current Thread [Next in Thread>